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Emerald ash borer found in Washington County

Emergency quarantine to follow

Minnesota Department of Agriculture employees confirmed the presence of emerald ash borer in Washington County for the first time Oct. 15.

A mature EAB was found in a survey trap located at the Minnesota Department of Transportation's St. Croix Rest Area along westbound Interstate 94 in West Lakeland Township.

"These survey traps are one tool we have to search for emerald ash borer in areas close to known infestations, as is the case in Washington County," MDA entomologist Mark Abrahamson said in a written statement. "With the help of these traps, private citizens on the lookout for signs of EAB, and private and public partners, we can identify new infestations of the insect early and take measures to slow its spread in the state."

MDA staff reported finding tunneling activity caused by the destructive pests in at least one ash tree at the rest area during a follow-up visit last week.

Allen Sommerfeld, MDA senior communications officer, said the EAB specimen had been sent to the United States Department of Agriculture, because it's the first time an ash borer has been found in the county. As of Friday, Oct. 16, his office was still awaiting official confirmation, but MDA officials are confident what they found is an adult emerald ash borer.

Washington County will soon become the 11th Minnesota county to be placed under emergency quarantine for EAB, according to a press release from the MDA.

Adult specimens are a green metallic color and around a half an inch long. The invasive beetles were first found in Michigan in 2002. According to the MDA, the insects, native to Asia, were first identified in Minnesota in St. Paul's St. Anthony Park neighborhood in May 2009.

The fussy, yet ravenous eaters only dine on ash trees. The USDA estimates that since their accidental introduction in the U.S., the insects have killed tens of millions of black, green and white ash trees in 24 states.

Minnesota has a virtually endless supply of food for the pests — boasting the highest concentration of ash trees in the country with approximately one billion.

Once the MDA receives confirmation of the EAB specimen, Washington County will join a list of 10 other counties under quarantine to help prevent EAB from spreading to new areas. Six of those counties are in the metro, including neighboring Anoka, Ramsey, and Chisago and Dakota counties. The other areas in the state under emergency quarantine are Hennepin, Scott, Fillmore, Houston, Olmsted and Winona counties.

The state and federal quarantine prohibits transporting ash trees, wood chips and firewood. Sommerfeld said EAB typically fly two or three miles on their own every year, but invasions spread quickly when people move firewood with the insects burrowed inside across the state.

The MDA urges people to buy firewood locally from approved vendors, and burn it where you buy it. They also encourage homeowners to watch ash trees on their property for signs of EAB infestation.

EAB larvae tunnel through the bark of an ash tree where they feed on the wood underneath. This feeding cuts off nutrients and moisture from traveling up through the tree up to its canopy, eventually killing it.

According to the Minnesota Department of Natural Resources, signs of an EAB infested tree include heavy woodpecker activity on the tree, dying branches in the top of the canopy, sprouts around the base of the tree, vertical cracks in the bark, S-shaped tunnels under the bark, and one-eighth inch D-shaped exit holes in the bark.

If you think your tree is infested, visit www.mda.state.mn.us/eab and use the "Do I have Emerald Ash Borer?" guide.